Caramel color manufacture

ABSTRACT

Caramel color is produced from fruit by heating the juice of the fruit in the presence of a caramelization catalyst and removing fruit flavor components during the process.

United States Patent Mohammad H. Anwar- Tappan;

Marvin Calderon, Hyde Park, both of N.Y. 791,131

Jan. 14, 1969 Nov. 9, 1971 Pepsi Co., Inc.

Long Island City, N.Y.

Inventors Appl. No. Filed Patented Assignee CARAMEL COLOR MANUFACTURE 9Claims, No Drawings U.S. Cl 127/34, 99/148 Int. Cl A233 3/32 Field ofSearch 99/148; 127/34 OTHER REFERENCES Winton et al., The Structure andComposition of Foods," 1935, Vol. 11, John Wiley & Sons, Inc., New York,pages 485, 486,567, 613, 706, (Copy in Group 172) PrimaryExaminer-Joseph M. Golian Attorney-Roylance, Abrams, Berdo & KaulABSTRACT: Caramel color is produced from fruit by heating the juice ofthe fruit in the presence of a caramelization catalyst and removingfruit flavor components during the process.

1 CARAMEL COLOR MANUFACTURE This invention relates to the manufacture ofcaramel color from fruit. More particularly, it relates to a process forthe manufacture of caramel color which is more economical than presentprocesses and is suitable for use in the production of beverages.

Caramel is a well-known and staple commercial material. It is anamorphous, dark-brown material that has been produced by the carefullycontrolled heat treatment of saccharine materials such as dextrose,invert sugar, lactose, malt syrup, molasses, sucrose, starchhydrolysates and fractions thereof, etc. The heavy-bodied, almost blacksyrup contains color components that impart the amber shade found incarbonated beverages, pharmaceutical and flavoring extracts, candies,soups, bakery products, and numerous other foods.

More recently, caramel has been employed as an emulsifying agent forwater insoluble materials. The employment of caramel in this manner isdescribed in Application Ser. No. 329,968 to Anwar and Calderon, filedDec. 12, 1963, the disclosure of which is hereby incorporated byreference. Thus, flavoring oils in carbonated beverages including orangeoil, lemon oil, distilled lime oil, grapefruit oil, and other citrusoils, clove oil, peppermint oil, ginger oil, wintergreen oil, cassiaoil, cinnamon oil, lemongrass oil, teaseed oil, etc. may be successfullysuspended in beverages employing caramel as the emulsifying agent. Thispermits the preparation of soft drinks without the need for emulsifyingagents, such as natural gums, which contain contaminants harmful toprocessing equipment and which have a deleterious effect on the finalbeverage, e.g., by causing oxidation or polymerization of the flavoringoils.

Caramel color has been produced commercially by heating highly refinedcorn sugars, in the presence of certain catalysts or reagents whichpermit the caramelization of the sugar. Caramelization involves thesimultaneous processes of inversion and reversion. Higher carbohydratemolecules in the refined sugars are hydrolized (inversion) underpressure, heat and acidity to simpler monosaccharides, which in turn,are polymerized (reversion) under the same conditions in conjunctionwith nitrogen and sulfur.

Refined sugars, such as dextrose and sucrose, have been employed forthis purpose. The dextrose, which is a monosaccharide, may be reactedwith the catalyst and it will polymerize under the influence of heat anda small amount of ammonia or ammonium salt to form the colored caramelproduct. Sucrose being a disaccharide, must-be hydrolyzed to formmonosaccharides before the addition of the catalyst for thecaramelization process. In order to produce a uniform caramel color withdefinite analytical standards with respect to tinctorial power (colorintensity), Baume, flavor, stability, etc., it has been the practice toemploy the highly refined sugars such as the corn sugars as the rawmaterial in producing caramel. Tremendous quantities of caramel colorare manufactured annually in the United States. lt has been estimatedthat annual caramel color production exceeds 100 million pounds. Theemployment of the highly refined carbohydrates in the caramelizationprocess is very costly. It would be highly desirable if less expensivecarbohydrates could be employed as the source of monosaccharide in thecaramel process.

Accordingly, it is an object of the present invention to produce caramelcolor from a relatively inexpensive source of carbohydrates.

A further object of the present invention is to provide caramel colorsuitable for use in beverages.

Another object of the present invention is to provide a relativelysimple process for the production of caramel color suitable for use inother products, such as baked goods, candies, pharmaceutical ointments,creams or lotions, hair dressings, suntan oils, cough syrups, polishes,etc.

Another object of the invention is to provide a caramel having a goodshelf life in that it will remain free flowing for long periods of time.

These and other objects of the present invention are accomplished by theprocess of the present invention which comprises forming an admixture offruit juice having a sufficiently high carbohydrate content tocaramelize and a caramelization catalyst, heating the admixture underpressure to caramelization temperature, continuing the heating for atime sufficient to caramelize the carbohydrate content of the fruitjuice, removing flavoring components from the caramelization product andcooling the resultant caramel color.

Surprisingly, it has been found that a high quality caramel color havinghigh acid stability can be simply produced from the carbohydrate contentof ordinary unrefined fruit and fruit juices. Thus, the process of thepresent invention employs those carbohydrates which are in natural,untreated fruit or the juice prepared from the fruit as the raw materialin the present caramelization process.

Suitable fruits that may be employed as the raw material for themonosaccharide starting material in the caramelization process in thepresent invention include the fruit of any seed bearing plant, forexample, apples, pears, peaches, grapes, dates, berries, figs, and thelike. In most fruits, there are suffrcient monosaccharides, i.e.,dextrose and levulose, present to polymerize and caramelize thus forminga highly suitable, colored caramel product. However, in those instanceswhere insufficient monosaccharides are present in the fruit, it may bedesirable to hydrolyze the polysaccharides therein to monosaccharides,that are suitable for the caramelization process. Any suitable means ofhydrolysis may be employed. Thus, for example, the polysaccharidecontent of the fruit may be hydrolyzed to monosaccharide by adjustingthe pH of the fruit to the proper level and heating for a predeterminedtime.

Any seed bearing fruit may be employed as a raw material for thecaramelization process of the present invention. However, it is usuallydesirable to convert the fruit to juice form in order to place it in aform suitable for use in the caramelization process.

In some cases, for instance in dates, carbohydrates are extracted in anaqueous system with the pits and other undesirable components beingremoved before the caramelization process. Any suitable caramelizationcatalyst may be employed in the caramelization of the carbohydratecontent of the fruit. A wide variety of such catalysts may be employedand these include, for example, acids e.g., acetic acid, citric acid,phosphoric acid, sulfuric acid and sulfurous acid; alkalis (e.g.,ammonium hydroxide, potassium hydroxide and sodium hydroxide); and salts(e.g., ammonium, sodium or potassium carbonates, bicarbonates, dibasicphosphates or monobasic phosphates). An especially preferredcaramelization catalyst for employment in the present invention isproduced by combining ammonia, sulfur dioxide, water and sodiumhydroxide to form the ammonium and sodium salts of sulfurous andsulfuric acid. Suitable amounts of the caramelization catalyst which maybe employed in the present process include between about 4 and about 20percent preferably between about 8 and about 16 percent based on theweight of dry salts against the total carbohydrate present.

The caramelization conditions employed for converting the fruit tocaramel color will be varied over a wide range and will depend, at leastto some extent, upon the particular color of caramel desired. However,suitable temperatures include those in the range of between about 222and about 350 F., preferably between about 230 and about 320 F. Thecaramelization process is conducted under pressure. The term underpressure" as employed herein includes pressures of between aboutatmospheric and about 75 p.s.i.g., preferably between about 10 and about60 p.s.i.g. The time required for caramelization may vary from betweenabout 2 hours and about 12 hours, preferably between about 4 and about10 hours depending upon the tinctorial power of caramel color desired.

The caramelization process may be suitably conducted by placing thefruit in a reaction kettle along with the careful addition of thecaramelization catalyst, e.g., ammonia, and ammonium and alkali salts ofsulfurous and sulfuric acid. This admixture is then heated underpressure for a period of, for example, l or 2 hours or for a timesufficient to give the ammonium and sulfite ions time to react initiallywith the sugars present. Water is released from the polymerization ofthe monosaccharide and from the color reaction. Next, a portion of thewater and the flavor components of the particular juice being treatedare removed so as to permit the production of a caramel of acceptableflavor and with as little flavor of the original fruit as possible. Itis essential that the flavor components be removed, since they canadversely affect the quality of the final product in which the caramelis employed.

The removal of the fruit flavor components may be conducted in anysuitable manner. For example, a flash distillation of the caramel may beachieved by merely releasing the pressure on the system so as to drivethe flavor components off. At this point the temperature of the systemmay be reduced to temporarily stop the caramelization reaction. Anothersuitable method which may be employed is, for example, steamdistillation of the caramel under pressure and continued caramelizationat the same time. However, flash distillation by pressure release is thepreferred method of conducting the flavor component removal portion ofthe process of the present invention.

After the flavor components are removed by flash distillation or thelike, the caramelization process may be resumed by increasing thetemperature of the system. The caramelization of the monosaccharides iscontinued until the desired color and quality of the caramel isachieved. Thus, the caramelization process may be continued for a periodof time between about 2 hours and about hours, for example. Next, theBaume of the finished caramel may be adjusted at this point if desired.Thus, cool water may be added to the system for the dual purpose ofdiluting the caramel and stopping the caramelization reaction. For thecaramelization process, the admixture of caramelization catalyst andfruit juice may be adjusted to a specific gravity of between about 25and about 40", preferably between about 29 and about 38.

The system comprising the caramel color may then be cooled and filteredor passed to a clarifying centrifuge, if desired, for the removal of anyinsoluble solids. For example, a filter press precoated with a filteraid may be employed. Finally, the pH of the caramel color may beadjusted to a desired level, e.g., between about 2.5 and about 3.5 pH,since the pH of the caramel may decrease as the reaction proceeds. Thisadjustment may be made by adding a solution of alkaline materials, suchas sodium hydroxide or potassium hydroxide.

In the foregoing manner, a caramelization process is provided employinga relatively inexpensive raw material, viz., fruit, as the source ofcarbohydrate in the production of the caramel color. The resultingcaramel has a good shelf life and will thus remain free flowing for longperiods of time. Also, the tinctorial power of the caramel may be variedover a wide range by the employment of the present process by merelyselecting the proper process conditions.

In addition, the caramel of the present invention has excellent acidfastness, i.e., a high stability in an acid solution.

It is highly important that the caramel for acidic beverages have suchstability because the presence of acids may tend to cause precipitationor sedimentation of color bodies from the caramel color itself. Theseflocs or sediment are highly objectionable in beverages since obviouslythey impair the appearance of the beverage.

Further, caramel produced by the process of the present invention may benegatively or positively charged depending on the nature of the productin which it is to be used. Thus, it will react with and precipitateoppositely charged colloids, but will help suspend other similarlycharged particles.

The raw materials for the process of the present invention may be fruit,the juice of such fruit or the concentrated juices of such fruit. 1f thestarting material is the whole fruit, it may be crushed and/or pressedin equipment conventionally employed for this purpose to form a juice orpuree. Next, the insoluble material, such as fibrous material, pectins,tannins, and proteinaceous materials may or may not be separated byfiltration or centrifuging or other appropriate means from the juice.However, such physical separation of these materials is not necessary atthis point in the process and may be done at the end of thecaramelization process.

In most instances, the monosaccharide content of the food issufficiently high that the caramelization of the fruit may now beconducted. However, as previously mentioned, if there is not sufficientmonosaccharide present for caramel production the carbohydrate in thefruit may be hydrolyzed in any suitable manner. Thus, for example, thepH of the juice may be lowered with a food grade acid, for example,phosphoric, citric, tartatic, fumaric, adipic, malic, or mixturesthereof, to a pH of between about 1.0 and about 3.0. The temperature ofthe mixture is then raised to between about 200 and about 250 F. for aperiod of between about 15 minutes and about 2 hours. Such treatmentconverts the polysaccharide content of the juice by hydrolysis tomonosaccharides.

Tl-le following examples will illustrate the practice of the presentinvention. They are presented for illustrative purposes only and shouldnot be construed as limiting the scope of the invention in any way.

EXAMPLE 1 A predetermined amount of apples are crushed and pressed intojuice form and are passed through a filter for the removal of fibrousmaterial and other insolubles The fruit juice is placed in a reactionkettle which may be coke-fired, gas-fired, Dowtherm or may be heated byhigh-pressue steam. Since the fruit has a sufficiently highmonosaccharide content, hydrolysis is not required at this stage. Theviscosity of the juice is adjusted to the desired concentration bydriving off a predetermined amount of water.

Next, a caramelization catalyst comprising a mixture of ammonia, andammonium and sodium salts of sulfurous and sulfuric acid is carefullyadded to the vessel and the temperature of the vessel is increased toabout 252 F. and a pressure of about 15 p.s.i.g. The fruitjuice-catalyst admixture is heated for about 2 hours under thispressure. Next, a valve is opened and the pressure is reduced toatmospheric, while lowering the temperature to about 215 to 220 F. Atthis point, water is distilled off along with volatile components whichcharacterize the flavor of the apple juice. The caramel color remainingin the vessel now has an acceptable flavor. The temperature is raised to275 F. and the caramelization process is continued under pressure for aperiod of about 5 hours. At the end of this time the specific gravity ofthe finished caramel is adjusted to about 2540 B. and the batch iscooled quickly by the addition of cool water and filtered. Next, the pHof the caramel color is adjusted to about 3.0 with the addition of analkaline material, e.g., sodium hydroxide.

The resulting caramel color is boiled in phosphoric acid for a period of5 minutes and is stored in a glass flask for a period of about 6 weeks.The resulting caramel color has excellent acid fastness and upon viewingthe flask at the end of this time it is seen that precipitation of colorbodies in the caramel has not occurred. Thus, it may be concluded thatthis caramel color is suitable for employment in beverages such ascarbonated soft drinks and the like.

EXAMPLE 2 Concentrated lemon juice having a specific gravity of betweenabout 25 and about 40 B. is pumped into a pressurized vessel and thetemperature is raised slowly to about 300 F. while under a pressure ofabout 65 p.s.i.g. Meanwhile, the catalyst of example 1 is slowly addedto the vessel and when the temperature reaches 300 F. the caramelizationis conducted for a period of about one hour. Next, a valve on thepressurized vessel is open and the lemon flavor components are releasedthus eliminating the characteristic lemon flavor from the caramel.

Next, the caramelization process is continued for a period of about 8hours after which time the temperature is quickly lowered on the systemand the pH of the product of the caramel color is adjusted to a desiredlevel.

The resulting caramel color is stable and remains free flowing for longperiods of time.

EXAMPLE 3 For comparative purposes, a single fold portion of lemon juiceis placed in a pressurized vessel and is concentrated to between about25 and about 40 B. The catalyst of the previous example is added and thecaramelization process is conducted in the manner described in example2.

The resulting caramel color is acid fast and has a good shelf life.

EXAMPLE 4 A portion of berries having an especially low monosaccharidecontent, but which have a sufficiently high polysaccharide content towarrant their use in the present caramelization process are concentratedto between about 25 and about 38 B. after being crushed and pressed. ThepH of the resulting berry juice is lowered to between about 1.0 andabout 3.0. The juice is then heated to a temperature of between about200 and about 250 F. for a period of between about 1 and 3: hours.During this time the polysaccharides in the fruit juice are hydrolizedto a large extent.

Next, a catalyst comprising ammonium suitite, ammonium sulfate, ammoniumbisulfite, ammonium bisulfate and the corresponding sodium salts, isadded to a reaction kettle containing the berry juice having anincreased monosaccharide content. The system is placed under pressureand the admixture is heated to a temperature of about 310 F. while undera pressure of about 70 p.s.i.g. After a period of about 1 and 56 hours,the admixture is cooled and is then subjected to steam distillation soas to drive off the berry flavor components.

The juice is now placed in a pressurized vessel and is heated to acaramelization temperature of about 300 F. while under a pressure ofabout 65 p.s.i.g. The caramelization is continued for a period of abouthours after which time the admixture is cooled to room temperature.

The resulting caramel color is placed in a one liter flask after aportion thereof has been boiled with a mixture of fumaric acid andadipic acids for a period of 5 minutes. The resulting acid-boiledmixture is clear thus indicating excellent acid fastness. The portion ofthe caramel color in the flask is stored for a period of 2 months. Thestored caramel has good shelf life and is free flowing.

EXAMPLE 5 A known amount of dates containing approximately 70 percentsugar is weighed into a tank. The tank is constructed in such a way thatit has a 10 mesh screen and false bottom. A predetermined amount ofwater is pumped into the tank and then agitation is started while thetemperature of the mixture is raised to about 200 F. After 30 minutes ofheating at this temperature the bottom of the tank is opened and theliquid is strained into a caramel cooker. This process is repeated twiceexcept that only one-fifth as much water is used in each washing and theheating cycle is cut down to minutes each.

The pits and pulpy cellulose material on the screen is discarded. To thecombined extract a caramelization catalyst comprising a mixture ofammonia and ammonium and alkaline salts of sulfurous and sulfuric acidsis added. The temperature of the cooker is raised to about 225 F. in aclosed system. After one hour of heating, the distillation valve isopened on top of the cooker. The condensate carrying the volatile flavorof the dates is collected until the liquid in the cooker reaches a Baumeof about 35. Since a large amount of heat is dissipated by thedistillation of steam, the temperature of 225 F. is maintained by thehigh pressure steam jacket.

At this point the distillation valve is closed and the temperature israised to about 275 F. corresponding to a pressure of about 35 p.s.i.g.Heat is maintained at this temperature until the desired color isobtained. Next,'the caramel is cooled as quickly as possible andfiltered at a temperature of to F. into the adjustment tank where itsBaume and pH are adjusted to the desired value before pumping andfurther cooling through a heat exchanger into the storage tank.

The following examples illustrate the employment of the caramel producedby the process of the present invention in the production of acarbonated beverage.

EXAMPLE 6 To 100 gallons of the caramel color produced in example 1,there are added 5 gallons of orange oil. This mixture is put through aManton Gaulin homogenizer which reduces the oil to small particles. Theresultant emulsion of orange oil is stable.

In a separate tank, there are mixed in sufficient water to make 500gallons of syrup, the following ingredients: 2.5 pounds of citric acid,3.0 pounds of sodium citrate, 2.5 pounds of sodium benzoate, 2,500pounds of sucrose, and 10 gallons of the emulsion of orange oil preparedas described above. This syrup is then diluted to 6 times its originalvolume with carbonated water to form an orange flavored beverage. Thebeverage is stable and has good color.

EXAMPLE 7 To 100 gallons of the caramel of example 4 there are added 7gallons of distilled lime oil and 3 gallons of lemon oil. This mixtureis put through a homogenizer which reduces the oils to small particleshaving an average particle size less than two microns. This emulsion isthen formulated into a flavored beverage as described in example 6. Astable beverage having good color is produced.

While the caramel color of this invention has been exemplified for usein flavored beverages, it is not limited to such use. Thus, the caramelprepared in accordance with the practice of this invention may also beused in the preparation of baked goods, candies, etc., where caramel isnormally used as a coloring agent.

Moreover, the caramel of this invention may be used to emulsify waterinsoluble materials other than flavoring oils. Thus, the caramel may beused to emulsify the water insoluble components which are used in thepreparation of pharmaceutical ointments, creams or lotions, hairdressings, suntan oils, cough syrups, polishes, etc., in which the colorimparted by the caramel will not be objectionable.

While the invention has been described in connection with specificembodiments, it will be understood that it is capable of furthermodification and is intended to cover variations without departing fromthe spirit and scope of the invention described in the appended claims.

What is claimed is:

l. A method for preparing caramel color which comprises forming anadmixture of fruit juice having a sufficiently high carbohydrate contentto caramelize and a caramelization catalyst, heating said admixtureunder pressure to caramelization temperature, continuing said heating atsaid caramelization temperature for a time sufficient to caramelize saidmonosaccharide content of said fruit juice, removing fruit flavorcomponents, subjecting the caramel color to further caramelization afterremoval of the flavor components, and cooling the resultant caramelcolor.

2. The method of claim 1 wherein said juice flavor components areremoved by releasing pressure on the system.

3. The method of claim 1 wherein the caramelization catalyst comprisesan admixture of ammonium and alkali salts of sulfurous and sulfuricacid.

4. The method of claim 1 wherein the caramelization temperature is inthe range of between about 230 and about 320 F.

5. The method of claim 1 wherein the fruit juice is obtained from fruithaving a sufficiently high monosaccharide content to caramelize and formcaramel color.

under a pressure of between about atmospheric and about 75 p.s.i.g.

9. The method of claim 8 wherein said admixture is heated under apressure of between about 10 and about 60 p s.i.g.

2. The method of claim 1 wherein said juice flavor components areremoved by releasing pressure on the system.
 3. The method of claim 1wherein the caramelization catalyst comprises an admixture of ammoniumand alkali salts of sulfurous and sulfuric acid.
 4. The method of claim1 wherein the caramelization temperature is in the range of betweenabout 230* and about 320* F.
 5. The method of claim 1 wherein the fruitjuice is obtained from fruit having a sufficiently high monosaccharidecontent to caramelize and form caramel color.
 6. The method of claim 1wherein the fruit is hydrolyzed to convert its polysaccharide content tomonosaccharides prior to being admixed with the caramelization catalyst.7. The process of claim 1 wherein the fruit juice has a concentration ofbetween about 25* and about 45* B.
 8. The method of claim 1 wherein saidadmixture is heated under a pressure of between about atmospheric andabout 75 p.s.i.g.
 9. The method of claim 8 wherein said admixture isheated under a pressure of between about 10 and about 60 p.s.i.g.